The most common analysis of materials used in multi-layer packaging bags and flexible packaging films is as follows:
Two-layer Polyester – Polyethylene:
The inner layer of this bag is food-grade polyethylene, while the outer layer is 12-micron polyester, printed on the back and laminated with the inner layer. This material is used for bags with polyethylene thickness ranging from 70 to 200 microns. Due to its transparency, it allows for the creation of a printed window and provides customers with a view of the product inside the bag, which is ideal for products that are not harmed by exposure to light. It is commonly used for packaging nuts, legumes, chocolates, herbal teas, dried vegetables, and fruits. By reinforcing the material and adding an additional transparent layer, the resistance to tearing, penetration, and settling can be increased, making it suitable for products like spices, sugar, candies, and olives.
Three-layer Polyester – Metallized – Polyethylene:
The inner layer is food-grade polyethylene, with the middle layer being metallized polyester, and the outer layer is 12-micron polyester, with printing on it. The three layers are laminated together, and this material is used for bags with polyethylene thickness ranging from 70 to 200 microns. This material is not transparent, so creating a window is not possible and is generally used for products sensitive to light. The metallized layer gives the packaging a silver color, which enhances the print’s brilliance. It is commonly used for packaging tea, coffee, nuts, export snacks, toffees, and chocolates.
Three-layer Polyester – Aluminum – Polyethylene:
This bag’s inner layer is food-grade polyethylene, the middle layer is aluminum foil, and the outer layer is 12-micron polyester, which is printed on and laminated together. This material is used for bags with polyethylene thickness ranging from 70 to 200 microns. Like the previous materials, it is not transparent and does not allow for the creation of a window. It is typically used for products sensitive to light. The aluminum layer increases the shine and beauty of the print. This material is often used for packaging cosmetics, chemical fertilizers, pesticides, tobacco, infant formula, and yeast.
Two-layer Paper – Polyethylene:
The inner layer of this bag is food-grade polyethylene, and the outer layer is paper, which is printed on and laminated with the inner layer. The polyethylene thickness can vary between 70 and 200 microns for bag production. A window can be created by adding an additional transparent layer and cutting part of the paper. This material is suitable for packaging flour, food powders, cookies, homemade sweets, dried vegetables, and medicinal herbs.
Three-layer Paper – Polyester – Polyethylene:
The inner layer is food-grade polyethylene, the middle layer is polyester, and the outer layer is paper, which is printed on. This material is used for bags with polyethylene thickness ranging from 70 to 200 microns. This analysis is suitable for paper window bags, offering not only the aesthetic appeal of paper but also good standing and protective capabilities. The paper in window bags provides a tactile experience, evoking a sense of recyclability and environmental sustainability. These bags are relatively inexpensive, diverse, and widely used, often for packaging nuts, dried fruits, spices, and herbal teas. The variety of paper colors such as writing paper, sulfite, glossy, and brown Kraft adds to the attractiveness of these paper window bags.
